Kenjoro Enterprises Limited is an Industrial Mineral Mining Company - Gypsum mining  in africa, especially in Kenya.
Geology and Mining
  Geology and Mining
Geology and Mining
Gypsum mining  in africa, especially in Kenya.
The geological of the Konza’s Kenjoro mining area consists of recent superficial deposits of black cotton soils, clays, gypsiferous beds, bentonite clays and Kapiti phonolites of volcanic origins.

Occasionally some thin beds and floats of white and impure Kunkar limestone are encountered within the mining concession.

The soils found on the Kenjoro mining area in Konza occurs as red marrum soils on the ridges and black cotton soils on the lowlands as well as the flat plains. The gypsum occurring fields are usually covered by the black cotton soils. The soils are generally smooth, fine and soft in texture and stubbornly sticky during the wet season. During the dry season the soil are hard and forms numerous cracks due to rapid evaporation characteristic of the area.

The blackish to grey swamp clays in colour are well developed under the black cotton soil due to poor drainage within the general terrain found within the Kenjoro’s mining area. Since the mining area falls on a poorly drained inland plain, the clays are wide spread and overlie the gypsiferous beds of the area. The clays are derived from the weathering of the Pleistocene sedimentary and volcanic ash deposits of the surrounding geological units.

Gypsiferous beds
Although rarely exposed on the surface within the area, the gypsum bed occurs within the Konza area at a depth of between 1.5 – 3 metres.
The gypsum ore deposit occurs as a crystal aggregate at varying depths associated with accumulation in hollows within the Kapiti phonolite geological unit rocks of the area. The gypsum aggregate deposits of the Konza area is inferred to have formed from the sulphated surface waters in a poorly drained soil environment. The sulphated waters were the derived products from the weathering of the upper deposit of Athi tuffs and the lake beds (Saggerson 1991). Chemical analysis of the gypsum aggregate deposits from the area gives gypsum content (CaSO4. 2H2O) of above 90%

Kapiti Phonolites
The Kapiti phonolites found in Konza area has been stratigraphically inferred to underlie all the volcanic and sedimentary units within Nairobi and the surrounding areas. This formation is therefore the oldest lava succession and forms the bedrock of the mining area. The rocks of this unit consist of large crystals of feldspar and waxy- looking nephinites set in a fine – grained dark green to black bluish – grey ground mass.

This rock deposit unit is a useful ballast and road stone raw material source in the surrounding districts and is a future resource of the area.


The gypsum aggregate deposits of the Konza area are found in relative shallow depths of between 1.5- 3 metres where they are over laid by loose unconsolidated soil and clay deposits.

The gypsum ore deposits are therefore mined by using simple stripping open cast mining method after stripping off the overlying black cotton soils and the clays.

The sequence of mining the gypsum ore is therefore as follows: 




Transporting to cement factories 


The following machinery and equipments are used to exploit the gypsum ore deposits at each of the following stages:-

  • Quarrying and mine openings
    • Caterpillar Hydraulic Excavators
    • Caterpillar wheel loaders
    • Tipper trucks
  • Natural drying
    • Caterpillar Backhoe loaders
  • Screening and Crushing
    • Screening and Crushing Plant
  • Transport and Dumping
    • Tipper truck lorries
    • Articulated tipper trucks
  • Others support tools
    • Headquarter office at Nairobi ( Mansour complex, witu road off Lusaka road)
    • Campsite offices and stores
    • Welding and repair tools
    • Diesel pump station
    • Electrical Generator
    • Other simple hand tools

Geological survey

Kenjoro enterprises limited has explored and performed a detailed geological survey on the mining area. The aim of this detailed geological survey was to delineate the mining area into mining blocks. They have been geologically mapped and Geo-chemically sampled to determine the quantity and quality of gypsum found in each block.
The result of this geological survey data has helped in the Kenjoro’s gypsum mineral production in determining the company’s quality control system for its future mining programs.

Kenjoro enterprises limited has interest in exploration for other gypsum deposited basins outside the Konza area. The company is exploring for Gypsum in Coast, North Eastern, Rift Valley and Eastern Provinces where gypsum deposits have been reported in the vast sedimentary basins.

Kenjoro enterprises limited has future plans to diversify and sell the surplus gypsum mineral products to other users.

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